scholarly journals Cerebral blood flow regulation in end-stage kidney disease

2020 ◽  
Vol 319 (5) ◽  
pp. F782-F791
Author(s):  
Justin D. Sprick ◽  
Joe R. Nocera ◽  
Ihab Hajjar ◽  
W. Charles O’Neill ◽  
James Bailey ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Kidney Disease ◽  
Cerebral Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Regulatory Mechanisms ◽  
End Stage Kidney Disease ◽  
Increased Risk ◽  
End Stage

Patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD) experience an increased risk of cerebrovascular disease and cognitive dysfunction. Hemodialysis (HD), a major modality of renal replacement therapy in ESKD, can cause rapid changes in blood pressure, osmolality, and acid-base balance that collectively present a unique stress to the cerebral vasculature. This review presents an update regarding cerebral blood flow (CBF) regulation in CKD and ESKD and how the maintenance of cerebral oxygenation may be compromised during HD. Patients with ESKD exhibit decreased cerebral oxygen delivery due to anemia, despite cerebral hyperperfusion at rest. Cerebral oxygenation further declines during HD due to reductions in CBF, and this may induce cerebral ischemia or “stunning.” Intradialytic reductions in CBF are driven by decreases in cerebral perfusion pressure that may be partially opposed by bicarbonate shifts during dialysis. Intradialytic reductions in CBF have been related to several variables that are routinely measured in clinical practice including ultrafiltration rate and blood pressure. However, the role of compensatory cerebrovascular regulatory mechanisms during HD remains relatively unexplored. In particular, cerebral autoregulation can oppose reductions in CBF driven by reductions in systemic blood pressure, while cerebrovascular reactivity to CO2 may attenuate intradialytic reductions in CBF through promoting cerebral vasodilation. However, whether these mechanisms are effective in ESKD and during HD remain relatively unexplored. Important areas for future work include investigating potential alterations in cerebrovascular regulation in CKD and ESKD and how key regulatory mechanisms are engaged and integrated during HD to modulate intradialytic declines in CBF.

Heparin Leakage by Advective-Diffusive Transport in Central Venous Catheters

2013 ◽  
Author(s):  
Patrick M. McGah ◽  
Michael Barbour ◽  
Alberto Aliseda ◽  
Kenneth W. Gow
Keyword(s):  
Blood Flow ◽  
Kidney Disease ◽  
Central Venous Catheters ◽  
Artificial Kidney ◽  
Diffusive Transport ◽  
End Stage Kidney Disease ◽  
Central Venous ◽  
Increased Risk ◽  
End Stage

Central venous catheters (CVCs) are used as a way to provide adequate access of blood flow for hemodialysis, a common treatment for end-stage kidney disease. During hemodialysis, the catheter must circulate up to 300 mL/min [1] of blood flow to the extracorporeal artificial kidney. Catheters contain two lumens: the inflow lumen provides flow to the artificial kidney, and the outflow lumen returns it to the patient’s circulation. Although catheters are used in the treatment of patients of all ages, this study is motivated by the use of central venous catheters for pediatric applications; the catheter types and calibers available for children are much more limited than for adults, thereby placing children in a further disadvantage and potentially subjecting them to increased risk of complications.

scholarly journals Cardiopulmonary exercise testing (CPET) in patients with end-stage kidney disease (ESKD): principles, methodology and clinical applications of the optimal tool for exercise tolerance evaluation

2021 ◽  
Author(s):  
Eva Pella ◽  
Afroditi Boutou ◽  
Aristi Boulmpou ◽  
Christodoulos E Papadopoulos ◽  
Aikaterini Papagianni ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Exercise Intolerance ◽  
End Stage Kidney Disease ◽  
Exercise Limitation ◽  
Cardiopulmonary Exercise ◽  
Functional Reserves ◽  
Increased Risk ◽  
End Stage

Abstract Chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), is associated with increased risk for cardiovascular events and all-cause mortality. Exercise intolerance as well as reduced cardiovascular reserve are extremely common in patients with CKD. Cardiopulmonary exercise testing (CPET) is a non-invasive, dynamic technique that provides an integrative evaluation of cardiovascular, pulmonary, neuropsychological and metabolic function during maximal or submaximal exercise, allowing the evaluation of functional reserves of these systems. This assessment is based on the principle that system failure typically occurs when the system is under stress and, thus, CPET is currently considered to be the gold-standard for identifying exercise limitation and differentiating its causes. It has been widely used in several medical fields for risk stratification, clinical evaluation and other applications but its use in everyday practice for CKD patients is scarce. This article describes the basic principles and methodology of CPET and provides an overview of important studies that utilized CPET in patients with ESKD, in an effort to increase awareness of CPET capabilities among practicing nephrologists.

Age dependence of brachial cuff-based ambulatory PWV in end-stage kidney disease patients undergoing long-term peritoneal dialysis

2021 ◽  
pp. 089686082199692
Author(s):  
Vasilios Vaios ◽  
Panagiotis I Georgianos ◽  
Georgia Vareta ◽  
Dimitrios Divanis ◽  
Evangelia Dounousi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Heart Rate ◽  
Peritoneal Dialysis ◽  
Kidney Disease ◽  
Pulse Wave ◽  
Age Dependence ◽  
End Stage Kidney Disease ◽  
End Stage

Background: The newly introduced device Mobil-O-Graph (IEM, Stolberg, Germany) combines brachial cuff oscillometry and pulse wave analysis, enabling the determination of pulse wave velocity (PWV) via complex mathematic algorithms during 24-h ambulatory blood pressure monitoring (ABPM). However, the determinants of oscillometric PWV in the end-stage kidney disease (ESKD) population remain poorly understood. Methods: In this study, 81 ESKD patients undergoing long-term peritoneal dialysis underwent 24-h ABPM with the Mobil-O-Graph device. The association of 24-h oscillometric PWV with several demographic, clinical and haemodynamic parameters was explored using linear regression analysis. Results: In univariate analysis, among 21 risk factors, 24-h PWV exhibited a positive relationship with age, body mass index, overhydration assessed via bioimpedance spectroscopy, diabetic status, history of dyslipidaemia and coronary heart disease, and it had a negative relationship with female sex and 24-h heart rate. In stepwise multivariate analysis, age ( β: 0.883), 24-h systolic blood pressure (BP) ( β: 0.217) and 24-h heart rate ( β: −0.083) were the only three factors that remained as independent determinants of 24-h PWV (adjusted R 2 = 0.929). These associations were not modified when all 21 risk factors were analysed conjointly or when the model included only variables shown to be significant in univariate comparisons. Conclusion: The present study shows that age together with simultaneously assessed oscillometric BP and heart rate are the major determinants of Mobil-O-Graph-derived PWV, explaining >90% of the total variation of this marker. This age dependence of oscillometric PWV limits the validity of this marker to detect the premature vascular ageing, a unique characteristic of vascular remodelling in ESKD.

Types of erythropoiesis-stimulating agents and risk of end-stage kidney disease and death in patients with non-dialysis chronic kidney disease

2020 ◽  
Author(s):  
Roberto Minutolo ◽  
Carlo Garofalo ◽  
Paolo Chiodini ◽  
Filippo Aucella ◽  
Lucia Del Vecchio ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Primary Endpoint ◽  
End Stage Kidney Disease ◽  
Short Acting ◽  
Erythropoiesis Stimulating Agents ◽  
Increased Risk ◽  
Significant Difference ◽  
Long Acting ◽  
End Stage

Abstract Background Despite the widespread use of erythropoiesis-stimulating agents (ESAs) to treat anaemia, the risk of adverse outcomes associated with the use of different types of ESAs in non-dialysis chronic kidney disease (CKD) is poorly investigated. Methods From a pooled cohort of four observational studies, we selected CKD patients receiving short-acting (epoetin α/β; n = 299) or long-acting ESAs (darbepoetin and methoxy polyethylene glycol-epoetin β; n = 403). The primary composite endpoint was end-stage kidney disease (ESKD; dialysis or transplantation) or all-cause death. Multivariable Cox models were used to estimate the relative risk of the primary endpoint between short- and long-acting ESA users. Results During follow-up [median 3.6 years (interquartile range 2.1–6.3)], the primary endpoint was registered in 401 patients [166 (72%) in the short-acting ESA group and 235 (58%) in the long-acting ESA group]. In the highest tertile of short-acting ESA dose, the adjusted risk of primary endpoint was 2-fold higher {hazard ratio [HR] 2.07 [95% confidence interval (CI) 1.37–3.12]} than in the lowest tertile, whereas it did not change across tertiles of dose for long-acting ESA patients. Furthermore, the comparison of ESA type in each tertile of ESA dose disclosed a significant difference only in the highest tertile, where the risk of the primary endpoint was significantly higher in patients receiving short-acting ESAs [HR 1.56 (95% CI 1.09–2.24); P = 0.016]. Results were confirmed when ESA dose was analysed as continuous variable with a significant difference in the primary endpoint between short- and long-acting ESAs for doses >105 IU/kg/week. Conclusions Among non-dialysis CKD patients, the use of a short-acting ESA may be associated with an increased risk of ESKD or death versus long-acting ESAs when higher ESA doses are prescribed.

Increased Inflammatory Response in Association with the Initiation of Hemodialysis Compared with Peritoneal Dialysis in a Prospective Study of End-Stage Kidney Disease Patients

2018 ◽  
Vol 38 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Kenneth Yong ◽  
Gursharan Dogra ◽  
Neil Boudville ◽  
Wai Lim
Keyword(s):  
Blood Pressure ◽  
Peritoneal Dialysis ◽  
Kidney Disease ◽  
Inflammatory Response ◽  
Prospective Study ◽  
End Stage Kidney Disease ◽  
Cvd Risk ◽  
Ckd Stage ◽  
End Stage

Background Large epidemiological studies have demonstrated an early survival advantage with the initiation of peritoneal dialysis (PD) compared to haemodialysis (HD). Chronic inflammation may contribute to atherosclerosis and cardiovascular (CVD) mortality in end-stage kidney disease (ESKD). We hypothesize that the initiation of HD in ESKD patients is associated with a greater inflammatory response compared with PD. Aims To examine the effects of initiating HD and PD upon inflammation and CVD risk markers in ESKD patients. Methods We per formed a pilot prospective study on 75 predialysis CKD stage-5 subjects comparing the effects of HD and PD upon high sensitivity C-reactive protein (hsCRP), interleukin(IL)-12, IL-18 and pulse wave velocity (PWV). Study visits were conducted 3 – 6 months before (baseline) and after (follow-up) initiation of dialysis Results Thirty-nine and 36 patients were initiated on HD and PD respectively. HD patients were older than PD patients (65.1 ± 2.1 vs 57.7 ± 2.7 years; p = 0.03) but had similar baseline systolic blood pressure (SBP), pulse pressure (PP), hsCRP, IL-12, IL-18, and PWV. At follow-up, HD patients had significantly increased hsCRP levels [5.2(3.7, 7.3) vs 1.7(1.0, 2.8)g/L; p < 0.001] compared to PD. Follow-up blood pressure, IL-12, IL-18, and PWV were similar between groups. A significant association remained between hsCRP and HD after adjustment for age, previous CVD, and residual urine output. Conclusion The initiation of HD was associated with significantly increased hsCRP compared to PD. Further study is required to determine the plausibility of inflammation as a potential underlying contributor to the observed early mortality difference between dialysis modalities.

scholarly journals Mild sodium reduction in peritoneal dialysis solution improves hypertension in end stage kidney disease: a case-report study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Luigi Vecchi ◽  
Mario Bonomini ◽  
Roberto Palumbo ◽  
Arduino Arduini ◽  
Silvio Borrelli
Keyword(s):  
Blood Pressure ◽  
Peritoneal Dialysis ◽  
Case Report ◽  
Kidney Disease ◽  
Substantial Reduction ◽  
End Stage Kidney Disease ◽  
Low Sodium ◽  
First Case ◽  
End Stage ◽  
Residual Diuresis

Abstract Introduction Blood Pressure (BP) control is largely unsatisfied in End Stage Kidney Disease (ESKD) principally due to sodium retention. Peritoneal Dialysis (PD) is the most common type of home dialysis, using a peritoneal membrane to remove sodium, though sodium removal remains challenging. Methods This is a case-study reporting two consecutive ESKD patients treated by a novel peritoneal PD solution with a mildly reduced sodium content (130 mmol/L) to treat hypertension. Results In the first case, a 78-year-old woman treated by Continuous Ambulatory PD (CAPD) with standard solution (three 4 h-dwells per day 1.36% glucose 132 mmol/L) showed resistant hypertension confirmed by ambulatory blood pressure monitoring (ABPM), reporting 24 h-BP: 152/81 mmHg, day-BP:151/83 mmHg and night-ABP: 153/75 mmHg, with inversion of the circadian systolic BP rhythm (1.01), despite use of three anti-hypertensives and a diuretic at adequate doses. No sign of hypervolemia was evident. We then switched from standard PD to low-sodium solution in all daily dwells. A six-months low-sodium CAPD enabled us to reduce diurnal (134/75 mmHg) and nocturnal BP (122/67 mmHg), restoring the circadian BP rhythm, with no change in ultrafiltration or residual diuresis. Diet and drug prescription were unmodified too. The second case was a 61-year-old woman in standard CAPD (three 5 h-dwells per day) suffering from hypertension confirmed by ABPM (mean 24 h-ABP: 139/84 mmHg; mean day-ABP:144/88 mmHg and mean night-ABP:124/70 mmHg). She was switched from 132-Na CAPD to 130-Na CAPD, not changing dialysis schedule. No fluid expansion was evident. During low-sodium CAPD, antihypertensive therapy (amlodipine 10 mg and Olmesartan 20 mg) has been reduced until complete suspension. After 6 months, we repeated ABPM showing a substantial reduction in mean 24 h-ABP (117/69 mmHg), mean diurnal ABP (119/75 mmHg) and mean nocturnal ABP (111/70 mmHg). Ultrafiltration and residual diuresis remained unmodified. No side effects were reported in either cases. Conclusions This case-report study suggests that mild low-sodium CAPD might reduce BP in hypertensive ESKD patients.

Effect of hypoxia and hypercapnia on neurohypophyseal blood flow

1986 ◽  
Vol 250 (1) ◽  
pp. H7-H15
Author(s):  
D. F. Hanley ◽  
D. A. Wilson ◽  
R. J. Traystman
Keyword(s):  
Blood Pressure ◽  
Carbon Monoxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Regions ◽  
Regulatory Mechanisms ◽  
Similar Increase ◽  
Regional Cerebral Blood ◽  
Pressure Controlled

Neurohypophyseal blood flow responses to hypoxia and hypercapnia were studied in pentobarbital anesthetized, paralyzed dogs. Arterial O2 content was lowered from control (18 +/- 2 vol%) to 8 +/- 1 vol% by either decreasing O2 tension (hypoxic hypoxia, HH) or by increasing carboxyhemoglobin saturation (carbon monoxide hypoxia, COH) at normal O2 tension. In all animals HH and COH resulted in similar increases in total cerebral blood flow (239 and 300%, respectively). Regional cerebral blood flow showed a similar increase for all brain regions except the neurohypophysis (NH). The NH increased its blood flow with HH (approximately 320% of control) but was unchanged with COH (117% of control). The responsiveness of NH blood vessels was tested under conditions of hypercapnia (10% CO2) and HH with blood pressure controlled by concurrent hemorrhage. The response of NH vessels to altered arterial O2 tension occurs independently of blood pressure. Systemic [H+] or CO2 tension produce only small changes in NH blood flow. These data suggest that hypoxic and hypercapnic regulatory mechanisms for the NH are different from those of other brain regions. The precise mechanism by which the NH hypoxic response occurs remains unclear, but our data suggest an important role for systemic arterial O2 tension and chemoreceptors.

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